Their actions need to be taken into the wider context of what was happening around them, I touch on it a little here in my notes about Laurel:

Laurel Takashima, was a double agent with an implanted personality, working for the pro Earth Homeguard. It was her that allowed the Minbari assassin into Varner's quarters and erased logs of the transport tube failure. This was being done to disrupt relations with the Vorlons and the Earth Alliance, by framing Sinclair for the assassination attempt and isolating Earth. Working through third parties (Del Varner and the Narn, who saw an opportunity to use a situation to their advantage and forge closer ties with the Vorlons and the Minbari) Homeguard make a deal with the extremist elements in the Wind Swords clan of the Minbari Warrior Caste opposed to the Babylon Project. They would have made an uneasy ally for the Homeguard, but also a readymade scapegoat for their actions, framing the Minbari for the attempt on Kosh’s life, and to hide Laurel’s role.

So was all of this, including her actions in The Gathering, planned to be revealed at some point, had they stayed with the character?